2022 Third report
Arctic Sea Ice Information Center, Noriaki KIMURA (Atmosphere and Ocean Research Institute, The University of Tokyo)

- Minimum ice extent will be about 4.56 million square kilometers in September. This is greater than in 2020 and less than in 2021.
- The Northern Sea Route will open around August 12, and the Canadian side except for Canadian archipelago will open around July 30.
- Sea ice will remain on the Canadian archipelago side of the Beaufort Sea.


The white line indicates the ice edge for 2022 and the colored lines for 2020 and 2021.


The Arctic sea ice extent on September 10, when the sea ice minimum will be about 4.56 million square kilometers. This is greater than in 2020 and less than in 2021. And, this is greater than the second report (about 4.44 million square kilometers).
Summer Arctic sea ice extent has been declining rapidly in recent decades. While the decline was less evident between 2013 and 2019, it declined again significantly in 2020. And on September 10, 2020, the Arctic sea ice extent was 3.77 million square kilometers, the second smallest after 2012. On the other hand, in 2021, sea ice remained from the Beaufort Sea to the Chukchi Sea, and the sea ice extent on September 10 was approximately 4.72 million square kilometers, a significant increase from the previous year. This year’s sea ice extent will be slightly smaller than in 2021 but considerably larger than in 2020, indicating that the sharp decline in 2020 was transitory.
The daily anomaly of the sea ice concentration in Figure 4 shows that sea ice the Russian side will retreat earlier than usual. On the Canadian side, sea ice melting will be slower than usual in July in the area from the Chukchi Sea to the Beaufort Sea, and more sea ice will remain in the Chukchi Sea in August and September than usual. This is likely due to the thick and firm sea ice more than 4-year-old extending from the Beaufort Sea to the Chukchi Sea, as seen in Figure 5.
Russian side
Sea ice will retreat almost at the same time and in similar distributions in 2021. The Northern Sea Route will open around August 12. The route opening date has been determined with some leeway, so the actual date may be a little earlier than this.
Canadian side
Sea ice from the Chukchi Sea to the Beaufort Sea will retreat at about the same time in 2020 and 2021. Sea routes of the Canadian side will open around July 30. Sea ice on the Canadian archipelago side of the Beaufort Sea will remain as it did in 2020 and 2021. This is due to the fact that old ice, more than 3 years old since its formation, is spread over this area following 2020, 2021 (Figure 4). Therefore, it is possible that the sea ice that remains may also be thicker, and caution should be exercised.
Prediction method

The prediction was based on two factors: “sea ice redistribution from winter to spring” and “sea ice age”. The sea ice redistribution was determined from the sea ice movement from December to the end of June, and the sea ice age was estimated by the backward tracking of sea ice up to four years. The parameters used were determined based on the following result of an accuracy validation.
Figure 6 indicates the results of comparison of the difference between observed (actual) and predicted sea ice extent in five regions, A1 to A5, based on the results for the 11 years from 2007 to 2011 and 2016 to 2021. PND+AGE+DIV/AGE, PND+AGE+ABSDIV, and PND+AGE are the methods used in the first report, the second report, and this third report (i.e., last year’s third report) respectively, where PND is the sea ice redistribution from winter to spring, AGE is the sea ice age, DIV/AGE is the mean divergence of sea ice, and ABSDIV is the accumulated absolute value of sea ice divergence.
In the first and second reports, new parameters have been added to the predictions to properly reflect the effects of old sea ice. However, we found that PND+AGE, which uses fewer parameters for prediction, has the highest accuracy in all areas, including areas A1 and A2, where the influence of old sea ice is significant. Based on this result, this third report uses the same PND + AGE method as last year’s third report.
You can also check the daily forecast and sea ice age data (daily and yearly) on Arctic Data archive System (ADS) at National Institute of Polar Research.
If you have any questions about satellite monitoring of the Arctic Ocean, sea ice forecasting, or the forecasting methods used here, please contact the Arctic Sea Ice Information Center(sea_ice@nipr.ac.jp)
The sea ice forecast and its basic research were started in GRENE, continued to ArCS Project, and has been conducted in ArCS II Project since 2020.